Sambucus nigra agglutinin is located in protein bodies in the phloem parenchyma of the bark.

The bark of some young woody stems contains storage proteins which are subject to an annual rhythm: they accumulate in the autumn and are mobilized in the spring. We show here that the bark phoem-parenchyma cells of Sambucus nigra L. contain numerous protein bodies, and that the bark lectin (S. nigra agglutinin) which undergoes an annual rhythm is localized in these protein bodies. The protein bodies in the cotyledons of legume seeds also contain lectin, indicating that lectins may be storage compounds themselves or may have a function in storage and-or mobilization processes.